A voice user interface (VUI) allows a human user to interact with an intelligent, electronic device (e.g., a computer) by merely “talking” to the device. The electronic device is thus able to receive, and respond to, directions, commands, instructions, or requests issued verbally by the human user. As such, a VUI facilitates the use of the device.
A typical VUI is implemented using various techniques which enable an electronic device to “understand” particular words or phrases spoken by the human user, and to output or “speak” the same or different words/phrases for prompting, or responding to, the user. The words or phrases understood and/or spoken by a device constitute its “vocabulary.”